"He made a conscious decision to take the arrester bed over the risks associated with entering the intersection at the bottom of the freeway. He made a brave decision and one that has potentially saved his life and the lives of other road users."

Although an investigation is continuing into the incident, SA transport minister Stephen Mullighan claims the truck driver may have been in too high a gear for the section of the freeway.

The incident follows a crash in August when a Transpacific tanker lost control at the bottom of the freeway and hit three cars, killing two people.

The speed limit on the freeway descent was reduced to 60km/h for trucks as a result and 90km/h for cars. Lawton says the reduced speed limit is having an impact and people are slowing down.

However, South Australian Road Transport Association (SARTA) executive director Steve Shearer wants the limit dropped to 40km/h for trucks, saying it will help prevent accidents.

"If you’re in a low gear because you have to do 40km/h or less you won’t get into trouble, you won’t need to use your brakes and you won’t accelerate to the point of speeding," Shearer says.

"As good as it is that the driver used the arrester bed, no driver should find themselves in that position and if they come down the road properly. You have to wonder why he got into that situation – he must have been going quite fast.

"The reality is, if you’re doing the right thing you’ll never need to go into an arrester bed."

Shearer says the police are praising the driver for using the arrester bed because they want to encourage others to do the same.

"After all the training and publicity some will still show up and do the wrong thing. The question is how do you stop that?"